Emergence and Reproductive Patterns in the Japanese Beetle, Popillia japonica (Coleoptera: Scarabaeidae)

Sex-biased emergence patterns are common in insects resulting in either protandry (males emerging before females) or protogyny (females emerging before males). The Japanese beetle, Popillia japonica Newman, has been shown to exhibit protandry but shows some characteristics of a protogynous species. For example, females mate and oviposit multiple times and this species displays last male sperm advantage. This study investigated the emergence and egg laying patterns of Japanese beetles in east-central Illinois. Although variation existed among study sites none showed protandry and overall they displayed protogyny. Females did not initiate oviposition until several days after emergence and the number of eggs laid remained relatively constant over time. Thus, emergence patterns and reproductive biology suggest Japanese beetles in this population may be protogynous

Emergence and Reproductive Patterns in the Japanese Beetle, Popillia japonica (Coleoptera: Scarabaeidae)

Sex-biased emergence patterns are common in insects resulting in either protandry (males emerging before females) or protogyny (females emerging before males). The Japanese beetle, Popillia japonica Newman, has been shown to exhibit protandry but shows some characteristics of a protogynous species. For example, females mate and oviposit multiple times and this species displays last male sperm advantage. This study investigated the emergence and egg laying patterns of Japanese beetles in east-central Illinois. Although variation existed among study sites none showed protandry and overall they displayed protogyny. Females did not initiate oviposition until several days after emergence and the number of eggs laid remained relatively constant over time. Thus, emergence patterns and reproductive biology suggest Japanese beetles in this population may be protogynous

Soil application of neonicotinoid insecticides for control of insect pests in wine grape vineyards

Abstract BACKGROUND: Soil application of systemic neonicotinoid insecticides can provide opportunities for long-term control of insect pests in vineyards, with minimal risk of pesticide drift or worker exposure. This study compared the effectiveness of neonicotinoid insecticides applied via irrigation injection on key early-season and mid-season insect pests of vineyards in the eastern United States. RESULTS: On vines trained to grow on drip irrigation, early-season application of imidacloprid, clothianidin, thiamethoxam and dinotefuran provided high levels of control against the potato leafhopper, Empoasca fabae. Protection of vines against Japanese beetle, Popillia japonica, and grape berry moth, Paralobesia viteana, was also observed after mid-season applications. Efficacy was poor in commercial vineyards when treatments were applied to the soil before irrigation or rain, indicating that vines must be grown with an irrigation system for efficient uptake of the insecticide. CONCLUSIONS: In drip-irrigated vineyards, soil-applied neonicotinoids can be used to provide long residual control of either early-season or mid-to late-season foliage pests of vineyards. This approach can reduce the dependence on foliar-applied insecticides, with associated benefits for non-target exposure to workers and natural enemies

Multistate Comparison of Attractants for Monitoring Drosophila suzukii (Diptera: Drosophilidae) in Blueberries and Caneberries

Drosophila suzukii Matsumara, also referred to as the spotted wing drosophila, has recently expanded its global range with significant consequences for its primary host crops: blueberries, blackberries, raspberries, cherries, and strawberries. D. suzukii populations can increase quickly, and their infestation is difficult to predict and prevent. The development of effective tools to detect D. suzukii presence in new areas, to time the beginning of activity within a crop, to track seasonal activity patterns, and to gauge the effectiveness of management efforts has been a key research goal. We compared the efficiency, selectivity, and relationship to fruit infestation of a range of commonly used homemade baits and a synthetic formulated lure across a wide range of environments in 10 locations throughout the United States. Several homemade baits were more efficient than apple cider vinegar, a commonly used standard, and a commercially formulated lure was, in some configurations and environments, comparable with the most effective homemade attractant as well as potentially more selective. All alternative attractants also captured flies between 1 and 2 wk earlier than apple cider vinegar, and detected the presence of D. suzukii prior to the development of fruit infestation. Over half the Drosophila spp. flies captured in traps baited with any of the attractants were not D. suzukii, which may complicate their adoption by nonexpert users. The alternative D. suzukii attractants tested are improvement on apple cider vinegar and may be useful in the development of future synthetic lure

Infestation of Wild and Ornamental Noncrop Fruits by Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a pest of small fruits and cherries, and has also been noted to infest a variety of wild, ornamental, and uncultivated hosts. Identifying alternative hosts is critical for pest management. Research objectives were to: 1) survey fruits in the field for natural infestation of D. suzukii, 2) determine the susceptibility of fruits in laboratory no-choice studies, and 3) evaluate short-range preference between simultaneously ripe alternative hosts and cultivated fruits in laboratory choice studies. Field surveys identified new hosts or confirmed previously reported hosts including: Berberis aquifolium Pursh, Oregon grape; Cornus spp., dogwood; Cotoneaster lacteus W.W. Smith, milkflower cotoneaster; Elaeagnus umbellata Thunberg, Autumn olive; Frangula purshiana (de Candolle) A. Gray, cascara buckthorn; Lindera benzoin (L.) Blume, spicebush; Lonicera caerulea L., blue honeysuckle; Morus sp., mulberry; Phytolacca americana L., pokeweed; Prunus avium (L.) L., wild cherry; Prunus laurocerasus L., cherry laurel; Prunus lusitanica L., Portuguese laurel; Rubus armeniacus Focke, Himalaya blackberry; Rubus spectabilis Pursh, salmonberry; Sambucus nigra L., black elderberry; Sarcococca confusa Sealy, sweet box; Solanum dulcamara L., bittersweet nightshade; and Symphoricarpos albus (L.) S.F. Blake, snowberry. High fruit infestations were observed in S. confusa during April–May and Lonicera spp. in June before most commercial fruits ripen. From both field and laboratory studies, there was no evidence of susceptibility during the estimated ripe period Crataegus L. ‘Autumn Glory,’ hawthorn; Ilex crenata Thunberg, Japanese holly; Nandina domestica Thunberg, sacred bamboo; Rhaphiolepis umbellata (Thunberg) Makino, yeddo hawthorne; Rosa acicularis Lindley, prickly rose; Skimmia japonica Thunberg, Japanese skimmia; and Viburnum davidii Franchet, David’s viburnum. Lastly, laboratory choice tests identified that several fall-ripening alternative hosts were more susceptible than ‘Pinot noir’ or ‘Pinot gris’ wine grapes. By understanding host use, growers can identify high-risk areas where coordinated action may reduce infestation of D. suzukii in crops.Keywords: spotted wing drosophila, fruit host, alternative host, host range, invasive pes

Population genomics of Drosophila suzukii reveal longitudinal population structure and signals of migrations in and out of the continental United States

Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States (U.S.) a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge of past migration events, population structure, and genetic diversity is needed. In this study, we sequenced whole genomes of 237 individual flies collected across the continental U.S., as well as several sites in Europe, Brazil, and Asia, to identify and analyze hundreds of thousands of genetic markers. We observed strong population structure between Western and Eastern U.S. populations, but no evidence of any population structure between different latitudes within the continental U.S., suggesting there is no broad-scale adaptations occurring in response to differences in winter climates. We detect admixture from Hawaii to the Western U.S. and from the Eastern U.S. to Europe, in agreement with previously identified introduction routes inferred from microsatellite analysis. We also detect potential signals of admixture from the Western U.S. back to Asia, which could have important implications for shipping and quarantine policies for exported agriculture. We anticipate this large genomic dataset will spur future research into the genomic adaptations underlying D. suzukii pest activity and development of novel control methods for this agricultural pes

Widespread establishment of adventive populations of Leptopilina japonica (Hymenoptera, Figitidae) in North America and development of a multiplex PCR assay to identify key parasitoids of Drosophila suzukii (Diptera, Drosophilidae)

In recent years, there has been an increase in the adventive establishment and spread of parasitoid wasps outside of their native range. However, lack of taxonomic tools can hinder the efficient screening of field-collected samples to document the establishment and range expansion of parasitoids on continent-wide geographic scales. Here we report that Leptopilina japonica (Hymenoptera, Figitidae), a parasitoid of the globally invasive fruit pest Drosophila suzukii (Diptera, Drosophilidae), is now widespread in much of North America despite not having been intentionally introduced. Surveys in 2022 using a variety of methods detected L. japonica in 10 of 11 surveyed USA States and one Canadian Province where it was not previously known to occur. In most surveys, L. japonica was the most common species of D. suzukii parasitoid found. The surveys also resulted in the detection of Ganaspis cf. brasiliensis (Hymenoptera, Figitidae), the recently-released biological control agent of D. suzukii, in six USA States where it had not previously been found. These new detections are likely a result of intentional biological control introductions rather than spread of adventive populations. A species-specific multiplex PCR assay was developed as a rapid, accurate and cost-effective method to distinguish L. japonica, G. cf. brasiliensis, the closely-related cosmopolitan parasitoid Leptopilina heterotoma (Hymenoptera, Figitidae) and other native parasitoid species. This dataset and the associated molecular tools will facilitate future studies of the spread and ecological impacts of these introduced parasitoids on multiple continents